Cartridge fuse



C. H. COLE CARTRIDGE FUSE Sept. 19, 1933.

Filed July 30, 1932 Patented Sept. 19, 193.3

UNITED STATES PATENT-OFFICE Application July 30, 11932.. Serial No.626,752

Claims.

This invention relates to electric fuses and more particularly to a fuseof the cartridge type having associated therewith visible means forindicating when the fuse has been burned out. One

5 object of the invention is to provide a fuse of this character havinga body portion in which the indicator is located and a side extensionserving not only as a carrier for a visible indicator but also servingas a handhold by means of which the m fuse may be grasped and easilyinserted or removed without danger of a persons fingers contacting withterminals at the end of the fuse and causing an electric shock to bereceived.

Another object of theinvention is to provide a cartridge fuse having aside extension formed integral with its tubular body of insulationthereby producing a fuse which is cheap to make and very strong andeliminates danger of the side extension being broken lose if it isdimcult to Withdraw the fuse from terminal'clips of the fuse Anotherobject of the invention is to permit the ends of the side extension orauxiliary compartmerit to be tightly closed and plugs constitutingclosures for the same firmly held in place by metal terminals carried byend portions of the body.

Another object of the invention is to provide a fuse having a visibleindicator associated therewith energized when the fusible strip of thefuse is burned through and to permit terminals of the fuse to be removedand a new fuse strip set in place when necessary without disturbing thevisible indicator.

Another object of the invention is to provide a fuse of the cartridgetype which is very simple in construction, cheap to manufacture and verystrong and durable and efficient in its operation. The invention isillustrated in the accompanying drawing wherein:

Figure 1 is a longitudinal sectional view through one specificembodiment of the invention;

Figure 2 is a transverse sectional. view taken on the line 2-2 of Figure1; I

Figure 3 is a longitudinal sectional view through a modified form offuse;

Figure 4 is an end elevation of the fuse shown in Figure 3;

Figure 5 is a longitudinal sectional view showing the invention embodiedin a cartridge fuse of the blade type;

Figure 6 is a fragmentary sectional view of a fuse having a slightlydifferent construction from that shown in Figure 1; K

Figure "l is a perspective view showing a fuse 55 of the improvedconstruction in use.

(Cl. 200l-21l) This improved fuse is of the cartridge type used inelectric installation and consists broadly of a tubular body 1 ofinsulation in which a fusible strip is disposed between terminals 2carried by ends of the body and a side extension 3 of insulation formedintegral with the body and constituting an auxiliary chamber orcompartment in which is located aglow lamp or other visible indicator 4adapted to be energized when the fusible strip is burned through. Asightopening 5 is formed in the side extension in order that the glow lampmay be seen and the side extension 3 serves not only to form anauxiliary compartmerit in which the glow lamp is located but also as ahandhold in order that the fuse may be readily grasped between theterminals 2 and removed from' the clips 6 or set in place without dangerof a persons fingers contacting with the clips or terminals of the fuseand causing a shock to be received. The side extension is pref erablyroughened in order that it will not be liable to slip from between apersons fingers during insertion or removal of the fuse. Therefore, theglow lamp will not be liable to be broken by the fuse slipping from apersons hand and dropping upon a floor.

The fuse illustrated in Figures 1 and 2 is of the type provided with aremovable fuse strip and consists of a body 7 formed of any suitableinsulating material such as porcelain, fiber, hard. rubber, or any othermaterial desired. The side extension 8 is also of insulating materialand formed integral with the body ,7 during molding thereof, as showninFigure 2. side extension which extends longitudinally of the body andis of less length, will be firmly anchored to the body and when the sideextension is grasped and a pull exerted in order to detach the fuse fromthe clips 6 there will be no danger of the side extension breakingloose. A sight opening 9 is formed intermediate the length of the sideextension and the end portions of the side extension are internallythreaded to receive threaded plugs 10 serving as closures for ends ofthe auxiliary compartment defined by the side extension. Before theplugs 10 are screwed into place a glow lamp 11 having a resistance 12associated therewith is thrust into the auxiliary compartment and byreferring to Figures 1 and i 2, it will be seen that the glow lamp andits resistance extend longitudinally in the auxiliary compartment andfit snugly therein so that they will be firmly held in place.

.. Conductors 13 for the glow lamp extend out- Therefore, this wardlythrough ends of the auxiliary compartment and when the plugs 10 arescrewed, into place the conductors will be prevented from moving out oftheir proper positions. Theends of 5 the conductors extend alongthreaded end portions 14 of the cylindrical body 7 and make contact withmetal sleeves 15 which are threaded upon the body and form portions ofend terminals for the fuse. Each of these sleeves has an internalannular flange 16 which bears against an end ,of the tubular body andagainst each flange fits a metal disk 17 formed with a transverselyextending slot 18. The strip 19 of the fusible metal extendslongitudinally through the main compartment defined by the cylindricalbody and has its end portions passed through slots of the disk 17 afterwhich the projecting ends of the fuse strip are bent to form anchors 20held in fiat contacting engagements with outer faces of the disks 17 bymetal caps or heads 21 which are threaded into the outer end portions ofthe sleeve 15. It will thus be seen that theconductors 13 and endportions of the fuse strip 19 make contact with the terminals carried bythe body and ordinarily current will pass from one terminal to the otherby way of the fuse strip whereas if the fuse strip. becomes burnedthrough the current will then pass through the glow lamp and resistance12 by way of the conductors 13 and the glow lamp will be illuminated.The illumination of the glow lamp which can be clearly seen through thesight opening will indicate-that the fuse strip of the fuse has beenburned through and the fuse can then be grasped by its side extensionand detached from the clips 6. It is then merely necessary to remove thecaps 21 and disks 1'7 and a new fuse strip can be easily applied and thefuse reassembled. The side extension not only permits the fuse to beheld and easily applied to or detached from the clips without danger ofa shock being received but also permits'the fuse to be easily held andprevented from turning in a persons hand while thecaps 21 are beingscrewed into place or removed. Since the sleeve 15 slightly overlaps theouter end of the plug 10 the plug will be held in place and preventedfrom working loose.

I have therefore, provided a fuse of the cartridge type having aremovable fuse strip and a visible indicator, the fuse strip andindicator being located in separate compartments and the glow bulbconstituting the visible-indicator prevented from being damaged by hotgases or the shock of an explosion whenthe 'fuse strip is burnedthrough. I have further provided a fuse of such construction that thefuse stripmay be renewed without disturbing the glow, lamp and inaddition have provided a fuse havingits cylindrical body of insulatingmaterial formed with a side extension defining an auxiliary compartmentto receive the glow lamp and in addition serving as a handhold by meansof which the fuse may be easily handled andset in place or removedwithout danger of a shock being received.

In the embodiment of the invention illustrated in Figures 3 and 4 theside extension 22 defining the auxiliary compartment and serving as ahandhold is formed integral with the body 23 of insulating material andwithin the auxiliary chamber is placed a glow lamp 224 corresponding tothe lamp 11 and viewed through the sight opening 25. A resistance 26corresponding to the resistance 12 is associated with the lamp 24 andconductors 27 extend outwardly through ends of the auxiliary compartmentwith their extended end portions terminating in bent ends forming Ispurs or anchors 28 seated in the depressions formed in portions of thebody 23 which project beyond ends of the side extension. Ends of theauxiliary compartment are closed by plugs 29 which have wedging fitwithin the side extension and each plug has its outer end portionenlarged to form a circumferentially extending flange 30 projectingradially of the plug. These flanges extend radially from ends of theside extension' about the circumference thereof and constitute abutmentsserving very effectively to prevent a persons fingers from slipping offof ends of the extension and engaging the terminals 31 or clips 6. Theterminals 31 are in the form of metal caps which fit tightly about theextended end portions of the body and serve not only as terminalsoverlapping and securing extended ends of the conductors 2'7 but alsobear against outer ends of the plugs 29 and secure the plugs in place.The strip 32 of fusible material extends longitudinally in the maincompartment defined by the cylindrical body and has its ends anchored toheads of the metal caps or terminals 31 in a conventional manner. Inthis form of the invention the glow lamp will be illuminated to indicatewhen the fuse strip 32 has been burned through but the fuse strip cannotbe renewed and the entire fuse must be discarded and a new one set inplace.

The fuse illustrated in Figure 5 isof the knife blade type and its body33 and side extension 34 are similar in construction to that shown inFigure 1 except that ends of the body terminate flush with ends of theside extension and are internally threaded to receive externallythreaded metal sleeves 35 taking the place of the sleeve 15 and formedwith external flanges 36 which bear against ends of the body when thesleeves are screwed into place. These sleeves 35 extend from ends of thebody and beyond the flanges 36 are externally threaded to receivecollars 38 by means of which the blades 39 are held firmly in place.These blades have inner tongues 40 to which ends of the strip of fusiblematerial 41 are secured by bolts or other suitable fasteners 42 andtherefore, when the fuse strip 41 is burned through the blades may beeasily released and a new fuse strip applied. 1

A glow lamp 43 corresponding to the lamp 11 together with a resistance44 is mounted within the auxiliary compartment defined by the sideextension 34 in such position that the glow lamp may be seen through thesight opening 45 and ends of the auxiliary compartment are closed byplugs 46 which are screwed into place and can be easily removed whennecessary. Conductors 47 extend outwardly between the plugs 46 and wallsof the auxiliary compartment and ends of the conductors are bent overagainst end edges of the body where they are engaged by the flanges 36which firmly grip them and establish a good connection between theterminals of the plug and the conductors, in order to permit current topass through and illuminate the glow lamp when the fuse strip is burnedthrough.

The modified construction illustrated in Figure'6 is very similar tothat shown in Figure 1 except that ends of the side extension 48 insteadof being closed by threaded plugs are closed by plugs 49 which arethrust into the auxiliary chamber. Each of these plugs has acircumferentially extending flange 50 about its outer end to engage anend of the side extension and limit inward movement of the plug andsince the mamas 3 sleeves of the metal terminals 51 bear against theouter ends of the plug: they will be firmly held in place. The terminals51 are similar in construction to those shown in Figure 1 and when theyare screwed upon the end portions of the body 52, they engage outer endsof the conductors 53 leading from the glow lamp 54 and permit ourrent topass through the glow lamp when the fuse strip 55 is burned through.

It will thus be seen that in all of the embodiments illustrated anddescribed there has been provided a fuse of the cartridge type having afuse strip extending longitudinally in a main compartment betweenterminals carried by the body and a glow lamp mounted in an auxiliarycompartment formed with a sight opening and having conductors extendingout of the auxiliary compartment and engaged with the terminals of thebody in order that current may pass through the glow lamp and associatedresistance to illuminate the lamp when the fuse strip is burned through.

I claim:

1. A fuse comprising a tubular body of insula tion having a tubular sideextension formed integral therewith and extending longitudinally of thebody and constituting a hand hold, the side extension being formed witha sight opening, plugs closing ends of said side extension, terminalscarried by end portions of said body and closing the same, a fuse stripextending longitudinally in said body between said terminals, and a glowlamp in said side extension having conductors extending to theterminals.

2. A fuse comprising a tubular body of insulation having a tubular sideextension formed integral therewith and extending longitudinally of thebody and constituting a hand hold, the side extension being formed witha sight opening, plugs closing ends of said side extension, terminalsclosing ends of said body and each includ ing a sleeve fitting about thebody and engaging a plug to retain the plug in place, a fuse stripextending longitudinally in said body and anchored to said terminals,and a glow lamp in said side extension having conductors extendingoutwardly through ends of the extension and secured between end portionsof the body and sleeves of the terminals.

3. A fuse comprising a tubular body of insulation having a tubular sideextension formed integral therewith and'extending longitudinally of thebody and constituting a handhold, the side extension being formed with asight opening, plugs closing ends of said side extensions, terminalsclosing ends of said body and each including a sleeve engaged with anend portion of the body, a fuse strip extending longitudinally in saidbody between said terminals, and a glow lamp in said side extensionhaving conductors extending outwardly from the extension and engagedwith said terminals.

4. A fuse comprising a tubular body of insulation having a tubular sideextension formed integral therewith longitudinally of the body andconstituting a handhold, plugs of insulation closing ends of the sideextension and having marginal portions extended to form abutment fiangesabout the ends of the side extension projecting radially therefrom andserving to prevent a persons fingers slipping off ends of the extensionwhen grasping the same, terminals closing ends of said body and eachhaving a sleeve fitted about the body between an end of the body and theside extension, and a glow lamp in the side extension having conductorsextending out through ends of the side extension and engaged by sleevesof the terminals.

5. A fuse comprising a tubular body of insulation having a tubular sideextension formed integral therewith longitudinally of the ,body andconstituting a handhold, plugs of insulation closing ends of the sideextension, the side extension being formed with a sight opening, a glowlamp in the side extension having conductors extending out from ends ofthe side extension, terminals closing ends of said body and eachincluding a sleeve carried by the body and gripping a conductor, aclosure carried by said sleeve, and a fuse strip extendinglongitudinally in the body with its end portions engaged with closuresof the terminals.

CLARENCE H. COLE.

